GWT Tree widgets swallow arrow keyboard events which make TextBoxes contained in TreeItems not respond to arrow keys

问题

Easily reproducible in GWT 1.6.4:

Tree tree = new Tree();
tree.addItem(new TextBox());

The problem lies with onBrowserEvent in Tree:

switch (eventType) {
  case Event.ONKEYDOWN:
  case Event.ONKEYUP: {
    if (isArrowKey(DOM.eventGetKeyCode(event))) {
      DOM.eventCancelBubble(event, true);
      DOM.eventPreventDefault(event);
      return;
    }
  }

Like a lot of GWT widgets, they don't subclass well. There has to be a simple trick I could swing for this?

回答1:

Solved this with a bit of a hack.

    m_tree = new Tree()
    {
        @Override
        protected boolean isKeyboardNavigationEnabled(TreeItem inCurrentItem)
        {
            return false;
        }

        @Override
        public void onBrowserEvent(Event event) {
            int eventType = DOM.eventGetType(event);

            switch (eventType)
            {
                case Event.ONKEYDOWN:
                case Event.ONKEYPRESS:
                case Event.ONKEYUP:
                    return;
                default:
                    break;
            }

            super.onBrowserEvent(event);
        }
    };

来源：https://stackoverflow.com/questions/1770978/gwt-tree-widgets-swallow-arrow-keyboard-events-which-make-textboxes-contained-in